How does it work?! (level)

I’d like to know how it works. How does Lingq determines in what level I am.
Is there a list somewhere. By example, if I know 9000 words I am intermediate 2 (or 1)… And how much it takes to change level??
Maybe it’s a weird question, I hope I explain what I wanted to know clearly…
Thanks in advance!

It’s based on known words in a particular language: Avatar Help

Keep in mind that you can choose lessons from any level at any time.

If you would like to study language - just enjoy learning it.
It isn’t so important what level you have.
It can be important only if you have to take an exam in this language.
But in this case it isn’t sufficient just to know a lot of words because the language exam consists of 4 parts: